NATS said it was restricting flights "in accordance with international civil aviation policy".

A NATS spokesman was quoted as saying: “The Volcanic Ash Advisory Centre has issued a forecast that the ash cloud from the volcanic eruption in Iceland will track over Europe tonight.

“NATS is working with Eurocontrol and our colleagues in Europe's other air navigation service providers to take the appropriate action to ensure safety in accordance with international aviation policy.”

EasyJet warned that the volcanic ash was moving further south and weather experts cautioned that the impact could last some days.

“Following the eruption of a volcano in Iceland yesterday, an ash plume has entered UK and Scandinavian air space overnight. As a result NATS have closed parts of UK air space and this is causing significant disruption to all airlines due to operate flights to / from the UK today,” an EasyJet spokeswoman said.

The ariline’s passengers are advised to check the website before they leave for the airport for any disruption information.

Airports operator BAA said: "Following advice from the Met Office the National Air Traffic Service has introduced restrictions to UK airspace this morning as a result of volcanic ash drifting across the United Kingdom from Iceland.

"These measures currently affect Aberdeen, Edinburgh and Glasgow airports which are closed but may also affect other parts of the UK later today.

"Passengers intending to fly today are asked to contact their airline for further information and should expect disruption in the coming hours."

“The closure of airspace is in keeping with the safety advice issued by UK air traffic control. Emirates continues to liaise with the UK and European ATC authorities to monitor the movement of the ash cloud,” a statement said.

“Emirates passengers in transit at Dubai today are being provided with hotel accommodation.

“Passengers that are yet to depart for UK-bound destinations from other Emirates gateways across the network are being contacted through the airline’s call centres and local offices.

“The airline has set aside a dedicated check-in area at Emirates Terminal 3 Dubai to look after the requirements of passengers affected by the cancellation of its UK flights today.”